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Biomedical subjects

Katsuhiro Uchiyama

Publications and source records attributed to Katsuhiro Uchiyama.

7 recordsLinked to original sources
PubMed2005

Ovarian fibroma (fibrothecoma) with extensive cystic degeneration: unusual MR imaging findings in two cases.

Two cases of ovarian fibroma (fibrothecoma) with extensive cystic degeneration are described. One case revealed a large multiloculated cystic mass with a small solid part. Each locule showed variable signal intensity on both T1- and T2-weighted magnetic resonance (MR) images. The other case revealed a parviloculated cystic mass with a small solid part. In both cases, the solid parts were located at the periphery of the mass and showed distinct low signal intensity on both T1- and T2-weighted MR images and slight enhancement. It should be noted that ovarian fibromas (fibrothecomas) with extensive cystic degeneration are a rare exception to the rule that solid components in a cystic adnexal mass imply malignancy.

Aged↗
PubMed2005

Noncardiogenic pulmonary edema as the first manifestation of pheochromocytoma: a case report.

We report here a case of pheochromocytoma presenting with noncardiogenic pulmonary edema, which is an unusual first manifestation of pheochromocytoma. Chest radiograph showed diffuse consolitaion and ground-glass opacity on both lungs. Neither pleural effusion nor cardiomegaly was present. High-resolution computed tomography (HRCT) showed widespread ground-glass opacity with fine intralobular reticular opacity (so-called "crazy-paving" appearance) and consolidation in a strikingly dependent distribution. The areas of ground-glass opacity and consolidation were sharply marginated by interlobular septa, showing a geographic appearance. The pulmonary edema and dyspnea resolved over three days without cardioactive or diuretic treatment. Noncardiogenic pulmonary edema is an unusual first manifestation of pheochromocytoma. It is important to recognize this unusual manifestation in the emergency situation.

Adrenal Gland Neoplasms↗
PubMed2003

Bronchoarterial ratio and bronchial wall thickness on high-resolution CT in asymptomatic subjects: correlation with age and smoking.

OBJECTIVE: The purpose of this study was to determine whether the values of the bronchoarterial ratio and bronchial wall thickness, as viewed during high-resolution CT, relate to age and smoking status in asymptomatic healthy subjects. SUBJECTS AND METHODS: High-resolution CT was performed prospectively in 85 subjects without cardiopulmonary disease. The subjects were divided into three groups according to age: 29 subjects were 21-40 years old; 29 subjects, 41-64 years old; and 27 subjects, 65 years or older. Both bronchoarterial ratios, defined as the diameter of the bronchial lumen divided by the diameter of its accompanying artery, and the T/D ratio, defined as wall thickness (T) divided by the total diameter of the bronchus (D), were measured at the segmental and subsegmental levels of the apical and posterior basal segments. Each calculated ratio was evaluated according to age and smoking status. RESULTS: Significant correlation was found between the bronchoarterial ratio and age (r = 0.768, p < 0.0001), with the bronchoarterial ratio increasing with age and exceeding 1 in 41% of subjects older than 65 years. No significant correlation was seen between the T/D ratio and age. No significant differences in bronchoarterial ratio and T/D ratio were seen between smokers and nonsmokers in subjects overall; but in the elderly group, the T/D ratio was significantly higher in smokers than in nonsmokers (p = 0.021). CONCLUSION: The bronchoarterial ratio is influenced by aging. The normal bronchoarterial ratio in a substantial number of subjects older than 65 years overlaps with the ratio considered to represent bronchiectasis. Thus, when this ratio is used for the quantitative analysis of pulmonary and cardiovascular disease, the influence of age should be considered.

Adult↗
PubMed2002

Effect of the rate of gadolinium injection on magnetic resonance pulmonary perfusion imaging.

PURPOSE: To determine whether the injection rate of contrast agent affects the dynamics of enhancement of the pulmonary parenchyma on magnetic resonance (MR) pulmonary perfusion imaging. MATERIALS AND METHODS: Fifteen healthy volunteers underwent enhanced MR pulmonary perfusion imaging to evaluate the effects of different injection rates. Injection rates were 1, 3, or 5 mL/second. Regions of interest (ROIs) were chosen in the lung and aorta to analyze the change in signal intensity over time. RESULTS: As the injection rate increased, the peak enhancement occurred significantly earlier (P = 0.0012), but the peak enhancement signal-to-noise ratio (SNR) value was not affected (P = 0.25). With the 3- and 5-mL/second injection rates, images of both the pulmonary circulation and systemic circulation were obtained separately. However, with 1 mL/second, higher enhancement of the aorta was overlapped with peak enhancement of the lung tissue. CONCLUSION: The injection rate affects the enhancement profiles of the pulmonary parenchyma.

Adult↗
PubMedDate not supplied

Relationship between CT findings of pulmonary tuberculosis and the number of acid-fast bacilli on sputum smears.

PURPOSE: To investigate the relationship between computed tomography (CT) findings in patients with active pulmonary tuberculosis (PTB) and the number of acid-fast bacilli (AFB) on sputum smears. METHODS: We reviewed CT scans of 173 patients with active PTB. The patients were divided into groups according to the number of AFB on sputum smears as follows: A, negative (n = 40); B, doubtful (n = 21); C, + (n = 34); and D, ++ or greater (n = 78). The presence or absence and the number of lobes that included micronodules, nodules, consolidation and cavitation, the number of cavities and the maximum diameter of the cavity lumen were noted. RESULTS: The frequency of micronodules and nodules did not significantly differ among the four groups. In contrast, the frequency of consolidation and cavitation increased with the number of AFB (P < .0001). Differences in the number of lobes involving micronodules, nodules, consolidation and cavitation were significant between Group D and the other groups (P < .0001), but not between Groups A or B and C. The number and maximum size of cavities significantly differed between Group D and the other groups (P < .0001). CONCLUSIONS: CT findings correlated with the number of AFB in sputum smears to some extent. However, CT findings do not reliably discriminate between smear-negative patients and those with very few AFB excreting smear-positive patients.

Case-Control Studies↗